Local functional state differences between rat cortical columns
Local functional state differences between rat cortical columns
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DOI：
10.1016/j.brainres.2005.04.002
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发表时间：
2005-06-14
期刊：
影响因子：
2.9
通讯作者：
Rojas, MJ
中科院分区：
文献类型：
--
作者：
Rector, DM;Topchiy, IA;Rojas, MJ
在安静睡眠 (QS) 期间，听觉咔嗒声和胡须抽搐期间的表面诱发电位 (SEP) 通常比清醒和快速眼动睡眠期间更大。然而，无论睡眠-觉醒周期如何，单次试验的 SEP 幅度都会在高值和低值之间周期性波动。为了检验状态无关波动代表各个皮质柱的局部功能性睡眠样状态的假设，我们检查了睡眠-觉醒周期中多个皮质位置的单次试验 SEP 振幅。双侧刺激在每个半球产生 SEP 振幅波动，通常是协变的 (r = 0.4)，但存在频繁的半球差异。两个相邻的胡须在同一侧同时抽动，在相邻的皮质柱中产生高度相关的 SEP（r = 0.9），并且经常发散。我们发现 QS 期间的差异比清醒时多 50%，这表明差异不是由记录噪音或刺激不一致造成的。局部 SEP 波动也遵循 QS 期间 δ 波信号的局部差异（r = 0.4），这表明类似的机制可能会调制 SEP。局部类睡眠（高 SEP 幅度）状态的持续时间取决于先前类唤醒（低 SEP 幅度）状态的持续时间（r = 0.5），表明先前功能状态周期的使用依赖性。由于SEP指标的波动与整个动物的睡眠状态无关。并且半球和附近皮质柱之间经常存在差异，这些数据支持这样的理论：类睡眠功能状态可能局限于至少与皮质柱一样小的大脑区域。 (c) 2005 Elsevier B.V. 保留所有权利。
Surface evoked potentials (SEPs) during auditory clicks and whisker twitches are usually larger during quiet sleep (QS) over waking and REM sleep. However, SEP amplitudes from single trials fluctuate periodically between high and low values regardless of sleep-wake cycle. To test the hypothesis that state-independent fluctuations represent local functional sleep-like states of individual cortical columns, we examined single trial SEP amplitudes from multiple cortical locations across sleep-wake cycles. Bilateral stimuli produced SEP amplitude fluctuations in each hemisphere that usually covaried (r = 0.4), but with frequent hemispheric differences. Two neighboring whiskers, twitched simultaneously on the same side, produced highly correlated SEPs in neighboring cortical columns (r = 0.9) with frequent divergences. We found 50% more disparity during QS over waking, indicating that the differences did not result from recording noise or stimulus inconsistency. Local SEP fluctuations also followed local differences in the delta wave signal during QS (r = 0.4), suggesting that similar mechanisms may modulate the SEP. The duration of the localized sleep-like (high SEP amplitude) state was dependent on the duration of prior wake-like (low SEP amplitude) state (r = 0.5), suggesting a use dependence of prior functional state period. Since SEP indicators fluctuated independently from whole animal sleep state,. and were frequently different between hemispheres and nearby cortical columns, these data support the theory that sleep-like functional states may be localized to brain regions at least as small as cortical columns. (c) 2005 Elsevier B.V. All rights reserved.